<%--
  Created by IntelliJ IDEA.
  User: 90557
  Date: 2020/12/28
  Time: 13:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>

        <%
            System.out.println("a.jsp页面执行了");
            Object user = session.getAttribute("user");
            //如果等于null，则还没登录
            if (user == null){
                request.getRequestDispatcher("/login.jsp").forward(request,response);
            }
        %>
    我是a.jsp文件
</body>
</html>
